1. Field of The Invention
The present invention relates generally to a height control system for a vehicle. More particularly, the invention is directed to deactivate height control when a vehicle body is lifted up with a jack, for example, during parking.
2. Description of The Background Art
Japanese Utility Model Publication No. 58-95307 discloses a height control system for a vehicle utilizing electronically controlled air suspension. The air suspension system includes air chambers filled with compressed air and shock absorbers for adjusting height levels between a vehicle body and wheels respectively. The height level adjustment is accomplished by supplying compressed air from an air source to the air chambers through height control valves or draining the compressed air in the air chambers for leveling the vehicle body at a standard height value.
However, in such a conventional height control system, when a vehicle body is lifted up by external means, for example, with a garage jack, the suspension system concludes that the vehicle body is higher than a standard height value due to variation in vehicular load and then drains the compressed air from air chambers completely to attempt leveling the vehicle body to the standard height value. When the vehicle is jacked down, a vehicle height extremely lower than the standard height value results. Thus, when the vehicle body is jacked down with the lowered vehicle height, a bottom of the vehicle body may actually contact the road surface. Therefore, a vehicle height control system which allows for variation in vehicle height caused by external means has been sought.